Volleyball is increasing in popularity as both a competitive and recreational sport. During warm weather, volleyball is commonly played in parks, in back yards, on beaches, and virtually anywhere where a fairly flat surface exists. Recreationally, volleyball is also widely played indoors during inclement weather. Competitively, volleyball is played both in-and out-of-doors by both amature and professional teams.
Typical volleyball equipment, especially for outdoor recreational use, consists of a pair of poles each commonly having a spiked or pointed lower end to engage into the ground, and a line tied between the upper ends of the poles to support a net, with the lower corners of the net being tied to adjacent portions of the poles. Anchor lines are employed to try to maintain the net in taut condition. The anchor lines extend from the top of the poles downwardly and away from the adjacent end of the net.
With the foregoing equipment it is difficult to maintain the support line extending along the top of the net sufficiently tensioned to prevent the net from sagging, especially after being struck by a ball or fallen into by players. To tighten the net, usually one end of the upper support line is loosened and then retied, which is difficult to accomplish due to the height of the top of the net.
A further drawback of the foregoing volleyball equipment is that the poles are rather long. For instance, poles designed to support the net at the 7 foot 115/8 inch regulation height for men's play are typically over 8 feet in length. Thus, the poles are not easily transportable from place to place in a car or other type of vehicle. Also, due to their lengths, the poles are cumbersome to store when not being used.
Efforts have been made to reduce the bulkiness of the volleyball equipment by constructing the poles in two sections that are detachably connected together by some type of coupling arrangement. For instance, if the pole sections are designed to be telescopically engagable with each other, a typical coupling arrangement consist simply of a threaded cross pin extending through aligned cross holes formed in the overlapping portions of the pole sections to engage a threaded nut, thereby to prevent the pin from becoming disengaged. Because such pole sections are typically constructed from standard sizes of round tubing, the interior of the outer tube is somewhat larger than the exterior of the inner tube, permitting the two tube sections to rock or otherwise move relative to each other, especially if there is any appreciable clearance between the cross pin and the cross holes formed in the two tubes. If the cross pin is tightened in an attempt to reduce the "play" beteween the two tube sections, the torque applied to the nut engaged on the threaded end of the cross pin could easily deform the outer tube into an oblong cross-sectional shape, thereby preventing the two tube sections from being slidable relative to each other.
Another typical manner of locking the two telescoping pole sections relative to each other is through the use of a threaded coupling assembly, having a first member fixed to the end of the outer pole section into which the inner pole section telescopes and a second collar member threadably engaged with the first coupling member to clamp against the inner pole section when the second collar member is tightened relative to the coupling first member. After the two pole sections are extended or retracted to their desired relative engagement, the two coupling members are tightened by rotation relative to each other. A common disadvantage of this type of coupling assembly is that if the two coupling members are overtightened, it is often difficult if not virtually impossible to manually loosen the coupling members. Another significant drawback of this type of coupling assembly is that the threads of the coupling members invariably become rusted, thereby making it extremely difficult to either tighten or loosen the coupling members. Also, if the volleyball equipment is used at the beach, sand invariably becomes lodged between the two coupling members and also between the pole sections and the coupling members to hinder not only the free telescoping movement of the pole sections, but also the rotation of the coupling members relative to each other.